Vibrating oxygen probe

ABSTRACT

A vibrating oxygen probe arrangement for measuring the oxygen content of molten steel bath and the like including an elongated lance pivotally mounted on a frame work which carries a vibrating motor driving an arm or connecting rod which in turn is connected to the lance above its pivotal connection to the frame and wherein the lower end of the lance has connected thereto an oxygen probe including an oxygen sensing cell structure to determine the concentration of the oxygen in the molten bath, the frame structure being provided with handles so that an operator may carry the vibrating lance and place the same in the vessel, the connecting rod having a universal connection with the rotary collar connected to the lance and with the eccentric pin connecting with the cam driven by the motor eccentrically. The lance is pivotally carried by trunnion bars which pivot in adjustable supports mounted on the frame, the trunnion bars adjustably connected to an adjustable collar of the split ring type that surrounds and holds the lance below the connecting rod coupling to the lance.

31 ite tates atent 11 1 Chang et a1;

[54] VIBRATHNG oxvoeiv Paone [75] Inventors: Yi-Chung Chang, Murrysville;

Nicholas M. Rymarchyk; Robert B. Greenstine, both of Pittsburgh, all of Pa.

Berry Metal Company, Harmony, I Pa.

[22] Filed: Jan. 26, 1973 [21] Appl. 'No.: 326,904

[73] Assignee:

[52] 11.5. CI..... 204/195 S, 204/1 T, 204/222, 266/34 A, 259/101 1 51' 1m. (:1. 00111 27/46, C21Q 7/00 [58] Field of Search 204/1 T, 195 S, 222, 223; 266/34 A, 34 L, 34 LM; 259/99-101 [5 6] References Cited UNITED STATES PATENTS 1,475,937 12/1923 Daniels 204/222 l,548,614 8/1925 Konigsberg 266/34 A V 1,995,998 3/1935 Nefedov..' 259/101 2,390,052 12/1945 Bernstorffet al..... 266/34 A 3,341,430 9/1967 Wickerham et a1 204/1 T 3,445,364 5/1969 1 Strickler 204/222 3,657,094 4/1972 Hans 204/195 S FOREIGN PATENTS OR APPLICATIONS 1,191,222 '5/1970 Great Britain 20'4/195 S 111 3,869,369 1451 Mar. 4, 1975 Primary Examiner-T. Tung Attorney, Agent, or Firm-Rihard J. Meyers [57] ABSTRACT A vibrating oxygen probe arrangement formeasuring the oxygen content of molten steel bath and the like including an elongated lance pivotally mounted on a frame work which carries a vibrating motor driving an arm or connecting rodrwhich' in turn is connected to the lance aboveits pivotal connection to the frame and wherein the lower end of the lance has connected thereto an oxygen probe including an oxygen sensing cell structure to determine the concentration of the oxygen in the molten bath, the frame structure being provided with handles so that an operator may carry the vibrating lance and place'the same in the vessel, the connecting rodhav'ing a universal connection with the rotary collar connected to thelance and with the eccentric pin connecting withthe cam driven by the motor eccentrically. The lance is pivotally carried by trunnion bars which pivot in adjustable supports mounted on the frame, the trunnion bars adjustably connected to an adjustable collar of the split ring type that surrounds and holds the lance below the connect ing rod coupling to the lance.

. 10 Claims, 7 Drawing Figures so a PATENTEDHAR 4W5 3.869.369

SHEET 2 Bj 2 FIG.6 L MdJ BACKGROUND OF THE INVENTION 1. Field of the Invention:

This invention relates to the use of oxygen probes in molten metallurgical baths and in particular in molten baths of steel. The invention relates to apparatus for measuring the oxygen content of the molten metal.

2. Description of the Prior Art The use of a probe for determining the oxygen content in liquid metals, as for example, molten steel, is known for instance from U.S. Pat. No. 3,619,381 and it is also known to provide for apparatus for stirring metallic melts, as for instance, shown in U.S. Pat. No. 2,390,052. However, it is noted that in measuring oxygen concentration in a liquid metal with a solid electrolytic cell, a stationary boundary layer of liquid metal next to the surface of the solid electrolyte inhibits flow of oxygen between the bath and the electrolytic cell and, therefore, affects the reading of the cell and an accurate measurement of oxygen concentration is difficult if not impossible to obtain. Relative movement between the solid elecrolyte andthe liquid metal reduces the thickness ofthe boundary layer and thus shortens the diffusional path for oxygen and consequently accelerates the establishment of equilibrium of oxygen flow back and forth between the bath and the sensing cell and, therefore, an accurate measurement of oxygen concentration in the bath can be obtained. This inven tion reduces the thickness of the stationary boundary layer and increases the sensitivity of the oxygen probe.

Summary of the Invention. I

It is a primary object of this invention to provide for a vibrated solid-electrolyte oxygen probe based on the concentration-cell principle for measuring oxygen content of molten metal in a container. The invention com: prehends coupling a vibrator and an oxygen probe of the solid electrolyte type in a holder for insertion of the sensing tip of the probe into the bath of molten-metal whose oxygen content is to be measured. The vibrator causes thesensing tip-to vibrate relative to themetal bath to achieve fast and accurate measurement of the oxygen content.

The response-time of the conventional oxygen probe is longer than that of the below disclosed novel vibrated oxygen probe, or in other words, the vibrated probe is eliminate the error of. measurement due to inhomogenity of the bath.

The novel arrangement of the lance holder frame of the lance in pivot trunnions below the connecting rodbetween the lance and the eccentric pin on the motor driven cam provides for a preferred movement of the lance and the oxygen cell in the bath to improve reliability of measurement of oxygen concentration. Universal movement of the connections of the connecting rod between the lance and the eccentric pin and cam provides for smooth uniform sweeping action of the lance and probe in thebath. Due to the geometric positioning of the trunnion barson the lance with respect to the overhead position of the connecting rod with the lance the amplitude of the movement of the lance and probe, therefore, can readily be adjusted.

These and other objects and advantages will become readily apparent by reference to the following description, appended claims and attached drawings.

Brief Description of the Drawings FIG. 1 is a general view of a vessel containing molten steel with the subject inventive vibrated probe arrangement extending therein;

FIG. 2 is a perspectiveview of a vibrating lanceprobe apparatus;

FIG. 3 is atop view taken essentially along line'3--3 of FIG. 2;

FIG. 4 is a sectional view taken essentially along line 4-4 of FIG. 2;

FIG. 5 is a partial vertical view of that structure shown in FIG. 4;- r

FIG. 6 is a partial view taken essentially along line 6-6 of FIG. 3; and

FIG. 7 is a diagram illustrating the amplitude of movement of the lance and oxygen probe thereon.

Detailed Description of the Preferred Embodiment cal connection, as for instance described in U.S. Pat.

No. 3,619,381 to G. R. Fitterer which is hereby incorporated by reference, and also by such published literature as On the Way: A Probe for the'Direct and Continuous Determination of the Oxygen Content of M01- ten Metals/33, The Magazine of Metals Producing, Sept. 1968', p. 75 to 81, and also publication .Oxygen Sensor: A New Base for Deoxidation Practices," D. A.

Dukelow et al., Journal of Metals, Dec. 1971, p. 22 to 25. i

Attention is now directed to FIGS. 2-6 wherein there is shown the vibrated oxygen probe apparatus 6 which includes a framework or holder frame 14 which carries by means of trunnion members or bars 16 the lance 8 which at the lower end is provided with the probe 10 carrying the sensing cell 12. The: holder frame comprises four rectangularly spaced upright frame members 18 which are connected to one another by upper ,and lower rectangularly spaced top and bottom frame portions 20-which are, as are theuprights l4, angle members. Each opposed pair of uprights 14 carry a U- shaped handle holder 22 on respective opposite sides of the centrally disposed trunnion bars 16(Each'trunnion bar 16 at its outer end'connects with an opposed upright'elong'ated bar or trunnion support member 24.

' These two upright upport members 24 are on opposite sides of one another in oriented with respect to the holder'handles and extend between the upper and lower frame members 20. Centrally located in each tip-'- right trunnion support bar 24 is a vertical trunnion adjusting slot 26 which allows each trunnion bar 16 to be adjusted vertically by means of the adjustable support structure which as seen in FIGS. 4 and includes a threaded bolt 28 havingits stem projecting outwardly through the vertically elongated slot 26 and has thereon a threaded nut 30 which in conjunction with the bolt 28 allows tightening of the adjustable support structure through the slot and on the upright trunnion support bar 24. The reduced outer end 32 of the trunnion bar or fulcrum rod is received in recess or slot 34 in the head portion 36 of the bolt 28 for free rotation. The central portion of each trunnion bar is provided with a recessed portion 38 (flat surfaces for tool turning'of trunnion 16) and the inner threaded end 40 which extends into opening42 in the split ring adjustable collar 44. As seen in FIG. 4 the collar is shown to be split at 46 so that the collar 44 may be adjustably clamped with the aid ofthreaded nut 48 on the threaded end 40 that engages the side of the adjustable collar 44. The split collar arrangement at the adjustable collar 44 affords'for a greater range of lance diameters. The adjustable support structure 30a permits the reduced or pivot end 32 of the trunnion to be adjusted vertically in the slot 26 with movement of the collar 44 upwardly or downwardly. The adjustable support structure a also allows for lengthwise adjustement of the trunnion bar between the upright support member 24 and the lance shaft 8 a of the lance 8. Through such an arrangement oftwo trunnion bars the lance 8 is allowed to be pivoted in a straight line between each of the handle portions 22 and about the pivot members 16 by the oscillating or vibrating mechanism 50 spaced above the pivot structures 16.

The vibrating or oscillating structure 50 comprises an electric motor 52 that is carried by motor support bracket 54 which is attached to two adjacent upright frame members 18 which also carry the holder handle '22 below it. The motor is attached to these upright members above the trunnion bars 16 and is provided with an upwardly extending output shaft 56 which is attached to and drives a circularcam plate or member 58 which has mounted thereon on its top an eccentric pin 60 which is radially outward of the shaft 56. The eccentric pin 60 which is fixedly connected to the cam has an upper ball joint end 62 to provide for a universal joint connection with a connecting rod 64 which has a universal connection with the rotary collar 66 which is fixedly attached around the shaft 8a of the lance 8 It is evident that the rotation of the cam 58 will cause the upper end of thelance 8, pivoted at the trunnion bars 16, 16, to reciprocate through the connecting rod 64 and the lower end of the lance and-consequently the sensing cell 12 will reciprocate in the opposite'direction at an amplitude determined by the position of the adjustable trunnion bars 16, 16 with respect to the position of the connecting rod 64, as shown in FIG. 7. In this FIG., 0 represents the displacement of the upper end of' the lance from its neutral position, as for instance, shown in solid line in FIG. 2. The reference character 1 represents the corresponding displacement of the probe from its central neutral position. The distance between the plane of the connecting rod 64 and the plane of the trunnion bar l6, 16 is represented by a; andb represents the distance between the plane of the trunnions and the plane of the lower end'of the lance that is connected with the sensing cell 12. Therefore, it is clear that the following relationship holds:

d/c b/a therefore,

d= (l /a) Therefore, it can be seen that by adjusting the vertical position of the trunnion bars 16, 16in the respective adjusting slots 26 in the trunnion support bars 24, 24 and the position of the adjustable collar 44 with respect to the lance shaft 8a, the amplitude of movement of the lower part of the lance can be adjusted. Consequently, as the trunnions are positioned vertically closer to the conecting rod, the said amplitude increases and vice versa. Also, the frequency of oscillation of the probe is determined by the number of revolutions per minute of the cam member 58. In FIG. 6 it can be seen that the motor shaft 56 is directly connected to the cam 58 so that the rotational speed of the cam is identical tothat 'above the connection of the adjustable collar 44 with the lance 8. The rotary collar 66 has an arm 68 which receives the universal ball joint connection 70 between the .connecting rod 64 and the rotary collar 66. The connecting rod is a turnbuckle construction to allow for adjustment and connection of the universal ball lar 66 like the adjustable collar 44is of the split ring 6 type as shown at 74 to afford a greater range of lance diameters.

of the drive motor. However, a gear train may be employed to link the motor and the cam so that the cam canbe made to rotate at a slower or faster speed. The same result may be achieved by using a variable speed drive motor.

From the foregoing it can be seen that vibration of the apparatus not only reduces the thickness-of the boundary layer between the sensing cell and its molten environment but also enables the sensing cell to contact fresh and representative oxygen concentrations all the time, thus, to give more accurate and reliable oxygen concentration reading of the bath.

The foregoing description and drawings merely explain and illustrate the invention and the invention is not limited thereto, except insofar as the appended claims are so limited, as those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from-the scope of the invention.

What is claimed is:

I. An apparatus for measuring the oxygen content of molten metal, comprising:

an elongated lance having an upper portion and a lower portion having an oxygen probe at its lower end, said oxygen probe having a solid electrolyte for measuring the oxygen concentration in the molten metal, l

a mounting frame supporting the lance upper portion and including trunnion means pivotally' mounting the upper lance portion on the frame,

drive cam means'onthe frame and operatively connected with the lance upper portion in vertically spaced relation from the trunnion means for imparting periodic movement to the oxygen probe, and

a motor means carried by the frame and drivingly connectedwith said cam means to provide for said periodic movement of the oxygen probe.

2. The invention according to claim 1, and

said frame having the lance extending therethrough and said trunnion means being mounted on side portions of said frame.

3. The invention according to claim 1, and

said frame being disposed in surrounding relationship about the upper portion of said lance and said trunnion means being disposed within said frame conmeeting with the side portions of the frame.

4. The invention according to claim 1, and

said drive cam means being spaced vertically above said trunnion means, the connection of the trunnion means with the lance and the connection of the cam means with the lance being in general vertical axial alignment with one another.

5. The invention according to claim 1, and

said trunnion means including a collar around the upper lance portion and trunnion bars extending from the collar and connecting with the sides of the mounting frame and having vertically adjustable means at the connection with the sides of the mounting frame for vertically adjusting the position of the collar with respect to'the cam means and with respect to the probe tip in order to vary the amplitude of movement of the probe.

6. The invention according to claim 5, and

the collar of the trunnion means being a split ring for snug adjustment of the trunnion bars and said split ring about the lance.

7. The invention according to claim 1, and

said trunnion means being provided with vertically adjusting means connectable with the sides of the frame for varying the elevation of the trunnion means with respect to the cam means in order to vary the amplitude of movement of the probe.

3. The invention according to claim 1, and

said cam means including an ecce'ntric pin mounted eccentrically with respect to the motor means and a connecting link having auniversal connection with the eccentric pin and a collar about the upper portion of the lance having a universal connection with the connecting link whereby the drive cam means applies a periodic movement to the lance about its pivotal connection with the trunnion means.

9. The invention according to claim 8, and

said collar being of the split ring type for adjustment thereof on the lance upper portion.

10. An apparatus for measuring the oxygen content of molten metal, comprising:

an elongated lance having an upper portion and a lower portion having an oxygen probe at its lower end which is provided with a solid electrolyte for measuring the oxygen concentration in the molten metal,

' a mounting frame supporting the lance upper portion and including 'trunnion means pivotally mounting the upper lance portion of the frame,

a drive cam means on the frame and operatively connected with the lance upper portion in vertically spaced relation from the trunnion means for imparting periodic movement to the oxygen probe,

- a motor means carried by the frame and drivingly connected with said cam means to provide for said periodic movement of the oxygen probe,

said mounting frame surrounding the upper portion of said lance,

said trunnion means having adjustable means connecting with the sides of the frame for varying the position of the trunnion means with respect to the cam means whereby the amplitude said probe may be varied,

said cam means and said trunnion means connecting with said upper lance portion in lance axis alignment to provide for pivotal movement of the lance about the horizontal axis of the trunnion means and in a vertical plane perpendicular to the pivotal axis .of the trunnion means, and

a means for changing the frequency of said pivotal movement.

of movement of 

1. An apparatus for measuring the oxygen content of molten metal, comprising: an elongated lance having an upper portion and a lower portion having an oxygen probe at its lower end, said oxygen probe having a solid electrolyte for measuring the oxygen concentration in the molten metal, a mounting frame supporting the lance upper portion and including trunnion means pivotally mounting the upper lance portion on the frame, drive cam means on the frame and operatively connected with the lance upper portion in vertically spaced relation from the trunnion means for imparting periodic movement to the oxygen probe, and a motor means carried by the frame and drivingly connected with said cam means to provide for said periodic movement of the oxygen probe.
 2. The invention according to claim 1, and said frame having the lance extending therethrough and said trunnion means being mounted on side portions of said frame.
 3. The invention according to claim 1, and said frame being disposed in surrounding relatioNship about the upper portion of said lance and said trunnion means being disposed within said frame connecting with the side portions of the frame.
 4. The invention according to claim 1, and said drive cam means being spaced vertically above said trunnion means, the connection of the trunnion means with the lance and the connection of the cam means with the lance being in general vertical axial alignment with one another.
 5. The invention according to claim 1, and said trunnion means including a collar around the upper lance portion and trunnion bars extending from the collar and connecting with the sides of the mounting frame and having vertically adjustable means at the connection with the sides of the mounting frame for vertically adjusting the position of the collar with respect to the cam means and with respect to the probe tip in order to vary the amplitude of movement of the probe.
 6. The invention according to claim 5, and the collar of the trunnion means being a split ring for snug adjustment of the trunnion bars and said split ring about the lance.
 7. The invention according to claim 1, and said trunnion means being provided with vertically adjusting means connectable with the sides of the frame for varying the elevation of the trunnion means with respect to the cam means in order to vary the amplitude of movement of the probe.
 8. The invention according to claim 1, and said cam means including an eccentric pin mounted eccentrically with respect to the motor means and a connecting link having a universal connection with the eccentric pin and a collar about the upper portion of the lance having a universal connection with the connecting link whereby the drive cam means applies a periodic movement to the lance about its pivotal connection with the trunnion means.
 9. The invention according to claim 8, and said collar being of the split ring type for adjustment thereof on the lance upper portion.
 10. An apparatus for measuring the oxygen content of molten metal, comprising: an elongated lance having an upper portion and a lower portion having an oxygen probe at its lower end which is provided with a solid electrolyte for measuring the oxygen concentration in the molten metal, a mounting frame supporting the lance upper portion and including trunnion means pivotally mounting the upper lance portion of the frame, a drive cam means on the frame and operatively connected with the lance upper portion in vertically spaced relation from the trunnion means for imparting periodic movement to the oxygen probe, a motor means carried by the frame and drivingly connected with said cam means to provide for said periodic movement of the oxygen probe, said mounting frame surrounding the upper portion of said lance, said trunnion means having adjustable means connecting with the sides of the frame for varying the position of the trunnion means with respect to the cam means whereby the amplitude of movement of said probe may be varied, said cam means and said trunnion means connecting with said upper lance portion in lance axis alignment to provide for pivotal movement of the lance about the horizontal axis of the trunnion means and in a vertical plane perpendicular to the pivotal axis of the trunnion means, and a means for changing the frequency of said pivotal movement. 